Admin can easily create custom fields for vendors while he is creating new products. While creating a custom field using Advance Custom Field, admin needs to select ‘Vendor Edits Allowed’ so that vendor can use that custom field. Right now the supported field types of ACF are text, textarea, number, url, select, email, WYSIWYG editor. The WYSIWYG editor will only work in edit product pages.
You can use ACF functions like the_field, get_field to display the custom field value for the product.
The plugin will work with ACF and Dokan free as well as PRO versions.